Roller rail unit



p 12, 1939- v H. H. H ARRIS 2,172,37 7

ROLLER RAIL UNIT Filed Nov. 16, 1957 INVENTOR Henry H. Harris BY Q 1 ATTORN EY5 Patented Sept. 12, 1939 UNITED STATES FATENT OFFICE 3 Claims.

My invention relates generally to industrial heat treating furnaces, such as carbonizing furnaces and the like, and specifically relates to the means employed within the furnace on which to move articles therethrough.

Articles to be heat treated are usually loaded onto fiat-bottomed supports, such as trays, boxes or the like. These supports are disposed on top of skid rails or tracks or on various types of roller rails and are then pushed through the furnace in tandem. The flat skid rails have been found to be unsatisfactory, both because of the destructive effects of the friction generated by the flatbottomed supports, and because of the injurious effects of the heat conditions within the furnace which. with the load bearing stresses. cause warping, buckling and bending of the rails.

Ordinarily, roller rails. that is. rails on which rollers are mounted, while not subject to the destructive effects of travelling friction to the same extent as are flat skid rails. are nevertheless subject to the injurious effects of furnace heat and work support and travel thereover, and are so formed that usually the entire roller rail must be replaced if any part thereof becomes worn or damaged through use. This is an expensive operation, and among the objects of my invention, therefore, is the provision of a roller rail unit comprising a shell having a number of independently replaceable axle and roller units secured therewithin.

A further object of my invention is the provision of a roller rail unit made up of relatively few and easily replaceable parts.

Other and related obiects of my invention will in part be pointed specifically, and in part be obvious from the following description of an illustrative embodiment.

In the drawing annexed hereto and made a 40 part hereof:

Figure 1 is a plan view of one form of roller rail unit constructed according to and embodying my invention;

Fig, 2 is in part a side elevational view and in 5 part a longitudinal sectional View; and

Fig. 3 is an enlarged transverse sectional view on the line 33 of Fig. 2.

Reference numeral Ill indicates my improved roller rail unit which comprises a substantially 50 hollow cylindrical shell I2, having formed therein a number of bosses I4, I4, in which axles or pins I6 are secured, about which axles or pins l6 rollers I8 are mounted for rotation, the upper portions of the rollers I8 projecting upwardly of the shell I2 through a slot formed in the top thereof permitting work supports to be moved upon the rollers.

Shell I2 comprises an elongated, generally cylindrical hollow member which is preferably formed as a casting of heat and corrosion resisting alloy, of nickel, chromium and iron composition. The casting can be made in one piece or in two pieces, and welded together as indicated at I9. A plurality of pairs of transverse, horizontally opposed, and inwardly directed apertured bosses I4, I4, are formed as an integral part of shell I 2, the pairs being spaced at equal distances apart within the hollow interior of said shell I2. A longitudinal roller slot 20 is formed at the top of shell I2 extending the full length thereof, the width of slot 26 being equal to the distance between opposed bosses l4, I4, and slot 20 being longitudinally aligned with the space between said bosses. As stated, shell I2 is cylindrical and the opposing, spaced-apart apertured bosses I4, I4 project inwardly from the side walls, with the space between the bosses and the slot width being equal. A channel is thus formed in shell I2 within which rollers I8 are placed.

Rollers I8 are preferably formed as one-piece castings of heat and corrosion resisting alloys, preferably of nickel, chromium and iron composition, as are axles or pins I6, which comprise short lengths of hollow cylindrical tubing, as shown in Figs. 2 and 3. Alloys having high wear resisting qualities as well as being resistant to heat and corrosion are preferably used for these parts. Roller I8 is formed of such thickness that when inserted into the interior of shell I2 through slot 20 and the hub 22 thereof aligned with the apertured bosses I4, I4, and kept in such position by axle or pin I6, which passes through the apertured bosses and the hub opening 22, sufficient clearance is left between the bosses I4, I4, and the sides of slot 20 so that roller l8 will rotate freely in such position. Roller I8 is of such diameter with respect to the height of shell I2, that when secured in the position shown in Fig. 3, the top of the roller will project above the top of the shell, as indicated at 50, in order that work supports can be moved through the furnace over the rollers.

The slot 20 may be covered, if desired, at those regions between the projecting portions of roller I8, as by means of plates 36 welded into slot 20, as indicated at 38, thereby keeping the inside of the shell relatively free of scale or other material which might clog the action of the rollers. Holes 38 in shell I2 and holes 36 in rollers I8 permit entering materials to drop out and also allow access to the interior of the rollers and the shell for cleaning purposes.

Axles or pins I6 are secured within shell [2 as by welded connections 30, but any convenient connection may be made. With the axles or pins l6 fixed within the bosses I4, l4, rollers l8 are free to rotate thereon, and the wear and friction is divided up between the roller hub and the axle or pin, the weight of the furnace load being distributed over the roller, axle or pin, the bosses and shell walls.

To form a continuous roller rail, a number of my elongated units ID are placed end to end, with the rollers upwardly, and extending the length of the furnace within which same are to be secured, and are locked in such relation by being placed within feet 32 secured on the furnace floor, or on elevated track or platform (not shown). Feet 32 are so shaped on the under side thereof as to rest flatly on the supporting structure, and have openings into which are received the flared Walls 34 of shell l2 to secure adjacent units together and to keep same from twisting or rolling out of alignment. Shells l2 are-secured within feet 32 as by a welded connection, indicated at 40, although if desired, any convenient connection may be made.

As stated above, rollers I8 and shell I2 are cored, as at 36 and 38, to provide for self cleaning or to permitaccess to the interiors of these sufilcient' members for cleaning. If desired, clearance may be provided between the floor of shell l2 and roller [8 to allow for any accumulation of scale which might occur during use.

T This would avoid the necessity for cleaning.

only that particular pin need be replaced to restore the entire unit to operating efficiency, and the time and expense of a complete replacement thus obviated.

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. A roller rail unit for use in heat treating furnaces comprising an elongated, hollow, cylindrical member having a slotted top and a plurality of opposed and spaced apart inwardly extending apertured bosses therewithin formed as an integral part thereof, pins passing through and supported by said bosses, and rollers supported by said pins for rotation about said pins between said bosses and upwardly through said slotted top.

2. A roller rail unit comprising an elongated, hollow cylindrical member having a longitudinal slot in the top thereof, a plurality of opposed and spaced apart apertured bosses formed within the hollow member, the space between said bosses being equal to the width of the longitudinal slot and aligned therewith, a plurality of rollers disposed within the hollow member, pins passing through said bosses and said rollers and providing journals for said rollers, and the upper portions of said rollers extending through the slotted top of the hollow member.

3. A roller rail for use in heat treating furnaces comprising an elongated hollow cylindrical shell having a longitudinal slot in the top there' of, a plurality of pairsof apertured and spaced apart bosses within the shell defining a roller channel therebetween substantially equal to'the' Width of the slot, a plurality of rollers within the shell, each of which is disposed between and aligned with a pair of bosses, a plurality of axles passing through said rollers and bosses, said rollers being mounted for rotation about said axles,

and means to secure the shell against rotary 40 

